In the wake of several major oil-train accidents in the U.S. and Canada in the last year, Inslee told the Department of Ecology to work with several other agencies, tribes and the federal government to outline risks, identify data and regulatory gaps, and recommend actions the state could take to limit the threat.

"The concerns of Washington citizens with respect to the safe transport of oil through our state must be re-examined in light of the rapid changes taking place," Inslee wrote Wednesday in a state directive to Ecology.

The call for more information isn't new. Even as lawmakers this spring left Olympia divided over how to deal with the growth in oil-train traffic, they budgeted extra money for Ecology's spills program to begin an assessment of the problem.

The governor's directive "parallels what we were talked to about doing during the session," said Ecology spokeswoman Lisa Copeland. Between 2008 and 2013, the amount of oil moved by rail across the country rose from 10,000 carloads a year to about 400,000 carloads.

Much of that increase is due to the massive growth in production from North Dakota, where crude output jumped from 150,000 barrels or so a day in 2008 to roughly 1 million barrels.

With production outpacing pipeline capacity and growth, as much as 17 million gallons of petroleum already makes its way to refineries in Washington and Oregon. That amount is likely to triple by the end of this year. Oil is often delivered by train to barges in the Columbia River, then ferried to refineries.

There are proposals to add new facilities in several places, including in Grays Harbor along the coast.

In his directive, Inslee urged Ecology to examine particular risks from delivery of lighter, potentially more-explosive Bakken crude from North Dakota. The amount crossing into the state has skyrocketed in the past five years.

Inslee told Ecology to examine how Washington could coordinate with neighboring states and Canada to reduce the possibility of deadly accidents or environmentally dangerous spills.

Inslee's order specifically requires Ecology to work with the Utilities and Transportation Commission and the Washington Military Department's Emergency Management Division to gather input from local emergency responders.

"Public interest in this issue is growing, and an increasing number of Washington State communities are calling for improved safety measures," Inslee wrote.

While Ecology is familiar with assessing oil-spills risks on water, the Emergency-Management Division has been collecting additional information from local responders, which will be helpful in assessing safety threats, said Linda Pilkey-Jarvis, spills preparedness manager for Ecology.

"We've studied the marine side for years," she said. "But we know little about rail when it comes to credible and implementable recommendations to make it safer."

In response to an emergency order from the U.S. Department of Transportation early last month, the state military department has been collecting information from rail companies about major shipments of Bakken crude through Washington.

"They have been told to provide to states the volume per week, the route and the impacted counties," said military department spokeswoman Karina Shagren.

Only railways carrying more than 1 million gallons per trainload were required to provide that information.

The state and some railroads battled over how much information should be kept confidential. The railroads tried and failed to get the state to commit to not releasing that information under public-disclosure laws.

But BNSF Railway, Portland & Western Railroad and Tacoma Rail still provided that information to the state, which has shared it with local jurisdictions. Union Pacific did, as well, even though it transported a small enough volume that it wasn't required.

Under Inslee's order, Ecology must produce a report with recommendations by October 1.

"We have a very short amount of time, and we are madly, madly working," Pilkey-Jarvis said.